Protected concrete pile



July 7, 931. if. s. HONBERGER PROTECTED CONCRETE PILE Filed ug. 28, 1926 .0\ /w/WN l f. \.y E 7/u// M Patented July 7, 1931 FRANK S. HONBERGER, F LOS ANGELES, CALIFORNIA PROTECTED CONCRETE :PILE

Applicationled August 28, 1926. Serial No. 132,074.

This invention has to do with concrete and similar piling or the like; and more particularly with reinforced concretepiling although the general as well as the particular object of the invention will be best understood from the following detailed description, yet it may be said preliminarily that the general object of the production of a concrete pile or the like that will have immunity or high resistance to the deteriorating action of the water in which it is placed, and at the same time be producible and usable at much lower cost and expense than the concrete pile which has been protected byV impregnation or other means throughout its whole length and mass.

Without going into the particulars of causes of concrete pile deterioration, it may be said broadly that most concretes using the average or standard cement deteriorates in sea water or in water containing magnesium sulphate in weak solution. The proposed remedy is to make the concrete of such physif cal composition as to make it as nearly as possible impervious, or coating it or treating 26 it so as to make it impervious. The making of average concrete impervious has now been proved to be practicable by methods of impregnation hereinafter referred to, and which methods completely seal the concrete against 30 entry of water. It has also been found that in order to prevent deterioration and disintegration of the reinforcing elements in a pile at the points in the pile where the reinl forcing elements are alternately subjected to the action of water and air (due to the risingV Y and lowering of water level), the only known practical mode of protection is to completely seal the reinforcements at such points. The zone of greatest reinforcement deterioration has been found to be at or somewhat above the water level. In those parts of a reinforced' concrete pile that are submerged and wherein the reinforcements are constantly wet, the deterioration of the reinforcements is very slow. But in those portions where the reinforcements are alternately subjected to action of water and air, or are subjected to the action of moist, and particularly moist salt air, the reinforcement deterioration is c0111- paratively rapid.V

It has, therefore, been found that while it is necessary for the complete protection of the upper part of the pile it should be sealed against entry of both moisture and air, and the reinforcements in those parts should therefore be sealed against contact with both moisture and air, yet for the protection of the lower parts of the pile it may be fully sufficient that the concrete need not be rendered impervious to water, but only need be of such composition as to prevent chemical disintegration of the cement itself.

ln the issued patents to Frank S. Honberger: No. 1,555,209, dated September 29, 1925, for method of treating concrete, and No. 1,555,208, dated September 29, 1925, for method of and apparatus forvtreating concrete, there are described processes for impregnation of concrete, processes that are particularly applicable to concrete piles and the like and result in their impregnation in such manner as to make the piles fully impervious to both liquids and gases. A reinforced concrete pile thus impregnated (and the impregnation usually permeates throughout the mass of the pile or permeates into the pile to considerable depth below the surface) the reinforcing rods are completely sealed against both moisture and air and are thereby protected from deterioration and disintegration. The impregnating substance most commonly used in the practice of these impregnating processes is asphalt; and the result of the process is to fill completely the interstitial voids of the concrete so that the contained reinforcements are entirely sealed.

It has, however, been found in practice that the total length of piles necessary to reach a suitable footing beneath the water varies quite considerably, whereas the length of piling above the water level is more or less standardized. In any case the length of piling above mean water level is only`a somewhat small part of the total pile length; and although it is economically and commercially possible to impregnate the whole length of even the longest pile, it becomes in the case of a pile 100 feet or so in length an operation of some magnitude to handle the pile and to provide mpregnating apparatus and chambers 0f Y impervious to moistureandair and wherein:

that has high'.rimnaunityA .from deterioration the lower palrtisgnot necessaifilyniadeimpervious. Such a pilemay be initially manufactured-entirely pre-cast-before placement, or it may be initially,in'afdefin'twofparts and i those two parts joined together lafter the lower, or wh at I may call the walten* submerged part, is placed. By whatever method the final pile is made, the result 'ineach case is; 'a pile Wpand. .i`nvolve`s.onlya comparatively 'short p y length pf g'inrpregnating or Yimpervious consary `these reinforcements may rbe .cut to'their crete. 'Thesiimmarygifesult oftheinyention is `{thus that a pilelofjgiventotallengthmaybe froduced` at. .considerably lower, '.cost. .than eretofore. i Y

I In. orderthatabetter understanding of fmy'.

N.inventi,on .more or; less.. i

be4 had I .willL YIproeed to a etailed description of `typical .forms ofpilesrthat embodytheinvention,.ref

. company'ing' drawings.

l..oneformoffinished pile;

'ere'nce' for :thi'slpurjpose being had Atofthe: ac-

Init aarawingg.:

Fig. 11s a ve 'tical.longitudinalisection of 2. is-fa sideelevati n offth'efupper part .Figis-asizmilar view, ofyetanother form. .Referring rstto .the formxofpiletypified in`r Figs.; 1 .and/2,V and` .which 1s the rtypical forni rvused 1 where. the ,exact depth 'to.V which fthepile, must be drivenfisnot known, I there 1 show apileconipos'ed of a lowersection A, an s upper. sectionv Bl and,V anrintermediate ,j uncture Section @.ISectionsA and B. are pre-castbe- A,forelthepille isjputig-ntoplace and section C, asfwill lbe'f'described, is poureda'ftersection A f. ,fhasfbeen .putintmp'lace and.V section B isheld r"Sectioni-AL of Ithe pile mayconstitute a suit- .gregatesltogethenwith.say, a suitablev percentc rage of .Ycilcanic earthorlashsufficient tol take.

:up theifree the, concrete ,and .thereby C0 prey-ent reaction; between that -freelinie and the magnesium. sulphate inthe water; YSuch compositionsgforthspurpesefare known-,to

pre-'cast of a length preferably greater than the distance to which the pilemust be driven below mean low water level. Although it is, of course, possible in some cases to select a length for section A that will bring its finished top end at just the point desired'when it has been footed upon the desired foundation, lyetfin lpractice this mayl not always be possible. Accordingly, in the usualpractice section VA will be driven until it is suitably footed, andifthenits upperpart will be broken olf so that its upper end as indicated at 12 inF-ig: ly'will then be at'the desired height with, relation to low water level. Breaking` away the 'concrete `of the upper end of the pile 4rwill leave exposed the upper projecting xends lila its reinforcements, and then if necesf'Ihe-upper .section B 'ofthe vpile hasfbeen previously pre-'cast to the lengthsuitable for the structure that is to be supported. 'That' lengthvwill correspond tothe height of the `structure abovelmean-low water level, and suchlength is thus one that 1 does not vary .greatly-for the large lmajority of pile sup- Y .ported structures. Y

l It is,l therefore, comparativelyfeasy and econoi'nical'toI pre-cast and .-im-pregnate the wupper pile section B. In-thef-orms shown in .Figs 1 and2 this upper-section B is castwith a cavity 13in its lower end and with itsreinforcing rods 14 `projecting vby suitable-distance belowY itslower end-as indicated at 14a.

After lower section 11i-isf dri-ven'- and its -top lprepared, as previously described, uppersection B is, then lplaced Iin Iposition over` lower section A and in about the -relation 'shown in '1. Then'thespace between the ends 'of' .the two sections'is-enclosedby a suitable mold or casing '15 and concrete is poured into the enclosed yspaceto fillit l'an'd-,to-fill the cavity 13, an open-ing inuipperfsectionB beingprovided .at A16 yfor Lthis purpose. .In the relative y positions in which the twossections are yplaced beforepouringofthe-central joint-section C,

their-ftwo-sets 'of reinforcing -rodsvloverlap teachy other andy interlock., asi-sshown in Fig. l.

Consequently' when' the-,joint section C lisn- .poured-and hasfset,it-becomesineffect'anfinftegral ,part of the .two lprecast lsections and .the whole pile ymade of the' .three sections-becomes, in. eect, one monolithic andcontinuously reinforced pile. Theformf 15 may be ither Jle'ft in ,place lorsubsequently removed .for'furtheruse Y. f y f v Now-ina pilethus cornposed'the upper-,part orsectionB is formed of `impregnated or Iimpervious concreteand, as-will readily beseen,

itsreinforcing -rods llll ffwithin that .impervious` concrete cannot be f-reached by. either those JSkil-ledinftheart and meednddetailed fmoisture or air.v :Inthelower submerged-section .A the watermay .have'acoinparatively will work up into the joint section C by capillary action so that the interstitial voids of section C are constantly filled with water regardless of the fact that section C is at least at times above the water level. Of course, it will be understood that it is of my invention that oint section C may be placed low enough as to be always beneath the water level and, therefore, always directly filled with water. But, as I have explained, it may be only necessary to have section C near enough to the water level that the water, by capillary or other action, will keep its interstitial voids illed regardless of the fact that the water level may be somewhat lower. The distance above water level to which section C will be at all times water filled, of course, depends upon the nature of the concrete and upon the sizes and forms of its voids; but whatever that distance is, the completed pile is so designed that the upper part of section C is never at any time high enough above water level that air can ever gain entry to any of its interstitial voids. Thus if section C is made of concrete constituted the same as that of section A, it will have the same high resistance to deterioration and reinforcement rods within the joint section C will not be subjected to deterioration and disintegration because they are constantly surrounded by water and never in contact with the air.

In an ordinary pervious concrete pile that Y has the same pervious constitution throughout its length, the water will rise within the pile and along the reinforcement rods to a certain more or less definite distance above the water level. As the water level rises and falls the water within the concrete correspondingly rises and falls and sets up what may be termed a sort of pumping action within the concrete. Above the highest point reached by the water in the concrete, the reinforcing rods are, of course. constantly exposed to air; below the lowest point reached by the water in the concrete the reinforcement rods are constantly surrounded by water; but between these two points, due to the pumping action of the water up and down, the reinforcement rods are alternately exposed to the action of water and air. Consequently, in a plain pile of that kind, the rods are subject to rapid deterioration throughout their lengths above the lowermost point reached by the water in the concrete.

My pile construction not only protects the uppermost parts of the reinforcing rods against air contact, but also eliminate completely in the pile that pumping action that in an ordinary pile subjects the intermediate portion to alternate water and air action. This is true whether the upper section B of the pile be entirely impregnated with asphalt or whether it is only impregnated a suitable depth below its surface. If the entire secwithin the scope:

i broken away after tion B has all its interstitial voids filled with impregnating substances, it is, of course, obvious that the water rising in joint section C can only rise to the top of that joint section;

and the top vof that joint section being always low enough with reference to low water level that section will always be filled with water. vConsequently in such a pile the reinforcing rods pass downwardly directly from a space in which they are entirely protected into a space in which they are always surrounded by water, and with no possibility of an intervening space or Zone in which they are alternating surrounded by water and air.

These conditions are also true even if the upper pile section B is not entirely impregnated with asphalt or the like. Suppose, for instance, that upper section B is impregnated from its side and end surfaces to a depth suiiicient to reach and coat all interstitially exposed surfaces of the reinforcing rods, but leaving what may be called an internal core of unimpregnated concrete, as indicated by dotted lines at 2() in Fig. l. Although the water rising through section C may, to a certain extent, move up and down in this centrall unimpregnated core, it cannot reach the reinforcing rods as they are imperviously sealed. Suppose, on the other hand, this central unimpregnated core to be large enough to take in partially or wholly the innermost of the reinforcing rod. The upper end of joint section C being arranged to be always below the lowermost reach of water in the concrete, the water that rises through joint section C will, of course, rise in the lower part of the unimpregnated core of section B. Although the water may work orpump up and down to some extent in this enclosed core, motion up and down is in the first yplace materially restricted because as the water moves up the air in the core unable to find exit is compressed and as the water moves down the air is rareiied. Consequently the distance through which pumping action takes place is greatly lessened. And although, of course, there will be some deterioration of the reinforcing rods wherever they are in contact either continuously or intermittently with the air, it is obvious that it is always the same air with which they are in contact and that the oxygen of that air will soon be consumed and rusting and further deterioration of the reinforcing rods will be stopped.

p In Fig. 3 there is shown a somewhat different form that may either be set in place and assembled, as has been described in connection with Figs. 1 and 2, or may be assembled completely before setting of the pile. The distinctive difference between the form of Fig. 3 and that of Fig. l is that in Fiom 3 lower section A had been pre-cast to a de nite length so that its upper end need not be setting. It is possible t0 

